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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The renal pelvis of the hamster has been studied by light microscopy (epoxy resin sections), transmission electron microscopy, and morphometric analysis of electron micrographs. Three morphologically distinct epithelia line the pelvis, and each covers a different zone of the kidney. A thin epithelium covering the outer medulla (OM) consists of two cell types: (1) granular cells are most numerous and have apically positioned granules which stain intensely with toluidine blue, are membrane-bound, and contain a fine particulate matter that stains light grey to black in electron micrographs. (2) Basal cells do not have granules, are confined to the basal lamina region, and do not reach the mucosal epithelial surface. The inner medulla (IM) is covered by a pelvic epithelium morphologically similar to collecting duct epithelium of IM. Some cells in this portion of the pelvic epithelium (IM) stain intensely dark with toluidine blue, osmium tetroxide, lead, and uranyl acetate. Transitional epithelium, which separates cortex (C) from pelvic urine, has an asymmetric luminal plasma membrane and discoid vesicles, each of which is similar to those previously observed in mammalian ureter and urinary bladder epithelia. Based on morphological comparisons with other epithelia, the IM and OM pelvic epithelia would appear permeable to solutes and/or water, while the transitional epithelium covering the C appears relatively impermeable. It would also appear that the exchange of solutes and water between pelvic urine and OM would involve capillaries, primarily, since morphometric analysis showed that both fenestrated and continuous capillaries of the OM were extremely abundant (greater than 60% of OM pelvic surface area) just under the thin pelvic epithelium.
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PMID:Ultrastructural organization of the hamster renal pelvis. 48 9

Two cases of Tangier disease are described in children from families unrelated to each other. Necropsy in one case, the first to be reported in this condition, showed large collections of cholesterol-laden macrophages in tonsils, thymus, lymph nodes, and colon, and moderate numbers in pyelonephritic scars and ureter. As the storage cells may be scanty in marrow, jejunum, and liver, the rectum is suggested as the site of choice for biopsy. The diagnosis was confirmed by demonstrating the absence of alpha-lipoproteins from the plasma of the living child, and by finding low plasma levels in both parents of both cases. The disease can be distinguished from other lipidoses by differences in the predominant sites of storage, staining reactions, and serum lipid studies.
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PMID:Pathology of Tangier disease. 511 27

In diet-induced potassium depleted rats, tissue potassium content of the renal medulla decreases and membrane-bound droplets form in the cytoplasm of medullary cells. To elucidate the interrelationship between medullary potassium concentration and intracytoplasmic droplets, ligation of the left ureter was performed on rats deprived of potassium for 2 weeks. Our results show that, even in the absence of supplemental potassium provision to the animal, a unilateral rise in tissue potassium of the ligated left kidney was significant. After 4 days of ligation, the left medullary potassium was 41.96 +/- 0.79 mEq/100 g dry weight compared to 32.51 +/- 0.84 mEq/100 g dry weight (P less than 0.001) of medullary potassium in the non-ligated right kidney. The rise in tissue potassium in the left kidney coincided with the dissolution of intracytoplasmic droplets. We conclude, that mechanical obstruction to urinary flow can dissolve storage droplets in medullary cells and that the lysis of droplets is made possible by the increase in medullary tissue potassium content.
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PMID:Effects of ureteral ligation on renal medullary lesions of potassium depletion. 631 93

An ultrastructural analysis of the ampulla and ureter of the cricket, Acheta domesticus, is presented. The excretory system of the cricket is unusual in that the 112 Malpighian tubules do not attach directly to the gut, but fuse to form a bladder-like ampulla which is joined to the colon by a muscular ureter. The ampulla consists of two cell types, primary and regenerative. Primary cells secrete large numbers of membrane-bound vesicles into the lumen and also appear to be involved in fluid reabsorption. Regenerative cells are very small and form a layer just beneath the basal lamina of the ampulla. They are believed to differentiate and replace sloughed off primary cells. The ureter is a muscular tube lined with cuticle which connects the ampulla (endoderm) with the colon (ectoderm). The probable origin and significance of the morphological modifications of the excretory system are discussed.
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PMID:Excretion in the house cricket (Acheta domesticus): ultrastructure of the ampulla and ureter. 1862 Feb 35